With re-election rates often hovering above 90 percent, open seats represent a critical factor in the Democrats’ quest for a House majority. New Mexico’s 2nd District has been an elusive target for years, as long as Rep. Steve Pearce has been on the ballot.

But the Republican congressman’s decision to run for governor opens up a majority-Hispanic district that could be vulnerable if an anti-GOP wave develops.

Pearce’s district is an expansive one that envelopes the southern half of New Mexico, forming a U-shape around Albuquerque. The Hispanic population of the 2nd District was 54 percent in 2015, according to the U.S. Census Bureau’s American Community Survey.

That’s a larger number than the voting-age and the voting-eligible population of the district, but the opportunity for Democrats to organize and for President Donald Trump to antagonize Hispanic voters is there.

Trump did fairly well in 2016, carrying the district 50 percent to 40 percent over Hillary Clinton, according to calculations by Daily Kos Elections. But Mitt Romney edged President Barack Obama 52 percent to 45 percent here four years earlier.

Pearce was first elected, 56 percent to 44 percent, over Democrat John Arthur Smith in 2002, when he won the open seat following GOP Rep. Joe Skeen’s retirement. Pearce represented the 2nd until 2008, when he opted to run for the U.S. Senate but lost in the general election to Democrat Tom Udall.

Democrat Harry Teague won Pearce’s open seat, 56 percent to 44 percent, over Republican Ed Tinsley in 2008 (while John McCain was carrying the district 50-48 percent). Teague held it for just two years until Pearce came back to defeat him, 56 percent to 44 percent.

Democratic strategists have had their eye on the district because of the Hispanic population, but talked about the seat as a long-term project. The buzz from the party accelerated briefly when Eddy County Commissioner Rocky Lara got into the 2014 race because she looked like a potentially strong candidate. But Pearce defeated her handily, 64 percent to 36 percent, and he won re-election last year, 63 percent to 37 percent.

New Mexico’s 2nd District could be an example of a seat where the incumbent makes the seat look more comfortably Republican than it really is. Pearce is regarded as a hardworking incumbent who is aware of the demographic changes of his district. Now it will be up to Republicans to nominate someone who can replicate his success.

Even with the open-seat dynamic, Democratic strategists aren’t initially pushing the race to the top of their target lists. But Pearce’s absence, a large minority population, and potential midterm backlash against Republicans is enough to push the seat onto the list of competitive districts.

We’re changing the Inside Elections race rating from Solid Republican to Likely Republican. Democrats probably still need a political wave in order to win the 2nd District, but Republicans can’t take the open seat for granted.

Correction 11:12 p.m. | An earlier version of this story misstated the result of the 2008 Republican Senate primary in New Mexico.